-A Guide To Indoor Air Quality

INDOOR AIR QUALITY CONCERNS

All of us face a variety of risks to our health as we go
about our day to day lives. Driving in cars, flying in planes,
engaging in recreational activities, and being exposed to
environmental pollutants all pose varying degrees of risk. Some
risks are simply unavoidable. Some we choose to accept because to
do otherwise would restrict our ability to lead our lives the way
we want. And some are risks we might decide to avoid if we had
the opportunity to make informed choices. Indoor air pollution
is one risk that you can do something about.
In the last several years, a growing body of scientific
evidence has indicated that the air within homes and other
buildings can be more seriously polluted than the outdoor air in
even the largest and most industrialized cities. Other research
indicates that people spend approximately 90 percent of their
time indoors. Thus, for many people, the risks to health may be
greater due to exposure to air pollution indoors than outdoors.
In addition, people who may be exposed to indoor air
pollutants for the longest periods of time are often those most
susceptible to the effects of indoor air pollution. Such groups
include the young, the elderly, and the chronically ill,
especially those suffering from respiratory or cardiovascular
disease.

WHY A BOOKLET ON INDOOR AIR?

While pollutant levels from individual sources may not pose
a significant health risk by themselves, most homes have more
than one source that contributes to indoor ar pollution. There
can be a serious risk from the cumulative effects of these
sources. Fortunately, there are steps that most people can take
both to reduce the risk from existing sources and to prevent new
problems from occurring. This booklet was prepared by the U.S.
Environmental Protection Agency (EPA) and the U.S. Consumer
Product Safety Commission (CPSC) to help you decide whether to
take actions that can reduce the level of indoor air pollution in
your own home.
Because so many Americans spend a lot of time in offices
with mechanical heating, cooling, and ventilation systems, there
is also a short section on the causes of poor air quality in
offices and what you can do if you suspect that your office may
have a problem. A glossary and a list of organizations where you
can get additional information are listed at the back of this
booklet.

WHAT CAUSES INDOOR AIR PROBLEMS?

Indoor pollution sources that release gases or particles
into the air are the primary cause of indoor air quality problems
in homes. Inadequate ventilation can increase indoor pollutant
levels by not bringing in enough outdoor air to dilute emissions
from indoor sources and by not carrying indoor air pollutants out
of the home. High temperature and humidity levels can also
increase concentrations of some pollutants.

Pollutant Sources

There are many sources of indoor air pollution in any home.
These include combustion sources such as oil, gas, kerosene,
coal, wood, and tobacco products; building materials and
furnishings as diverse as deteriorated, asbestos containing
insulation, wet or damp carpet, and cabinetry or furniture made
of certain pressed wood products; products for household cleaning
and maintenance, personal care, or hobbies; central heating and
cooling systems and humidification devices; and outdoor sources
such as radon, pesticides, and outdoor air pollution.
The relative importance of any single source depends on how
much of a given pollutant it emits and how hazardous those
emissions are. In some cases, factors such as how old the source
is and whether it is properly maintained are significant. For
example, an improperly adjusted gas stove can emit significantly
more carbon monoxide than one that is properly adjusted.
Some sources, such as building materials, furnishings, and
household products like air fresheners, release pollutants more
or less continuously. Other sources, related to activities
carried out in the home, release pollutants intermittently. These
include smoking, the use of unvented or malfunctioning stoves,
furnaces, or space heaters, the use of solvents in cleaning and
hobby activities, the use of paint strippers in redecorating
activities, and the use of cleaning products and pesticides in
housekeeping. High pollutant concentrations can remain in the air
for long periods after some of these activities.

Amount of Ventilation

If too little outdoor air enters a home, pollutants can
accumulate o levels that can pose health and comfort problems.
Unless they are built with special mechanical means of
ventilation, homes that are designed and constructed to minimize
the amount of outdoor air that can leak into and out of the home
may have higher pollutant levels than other homes. However,
because some weather conditions can drastically reduce the amount
of outdoor air that enters a home, pollutants can build up even
in homes that are normally considered leaky.

HOW DOES OUTDOOR AIR ENTER A HOUSE?

Outdoor air enters and leaves a house by: infiltration,
natural ventilation, and mechanical ventilation. In a process
known as infiltration, outdoor air flows into the house through
openings, joints, and cracks in walls, floors, and ceilings, and
around windows and doors. In natural ventilation, air moves
through opened windows and doors. Air movement associated with
infiltration and natural ventilation is caused by air temperature
differences between indoors and outdoors and by wind. Finally,
there are a number of mechanical ventilation devices, from
outdoor vented fans that intermittently remove air from a single
room, such as bathrooms and kitchen, to air handling systems that
use fans and duct work to continuously remove indoor air and
distribute filtered and conditioned outdoor air to strategic
points throughout the house. The rate at which outdoor air
replaces indoor air is described as the air exchange rate. When
there is little infiltration, natural ventilation, or mechanical
ventilation, the air exchange rate is low and pollutant levels
can increase.

WHAT IF YOU LIVE IN AN APARTMENT?

Apartments can have the same indoor air problems as single family
homes because many of the pollution sources, such as the interior
building materials, furnishings, and household products, are
similar. Indoor air problems similar to those in offices are
caused by such sources as contaminated ventilation systems,
improperly placed outdoor air intakes, or maintenance activities.

Solutions to air quality problems in apartments, as in homes and
offices, involve such actions as: eliminating or controlling the
sources of pollution, increasing ventilation, and installing air
cleaning devices. Often a resident can take the appropriate
action to improve the indoor air quality by removing a source,
altering an activity, unblocking an air supply vent, or opening a
window to temporarily increase the ventilation; in other cases,
however, only the building owner or manager is in a position to
remedy the problem. (See the section What to Do If You Suspect
a Problem on page 30.) You can encourage building management to
follow guidance in EPA and NIOSH s Building Air Quality: A Guide
for Building Owners and Facility Managers. It is available for
$24 from the Superintendent of Documents, P.O. Box 371954,
Pittsburgh, PA 152507954; stock # 055000003904.

INDOOR AIR AND YOUR HEALTH

Health effects from indoor air pollutants may be experienced soon
after exposure or, possibly, years later.

Immediate effects may show up after a single exposure or repeated
exposures. These include irritation of the eyes, nose, and
throat, headaches, dizziness, and fatigue. Such immediate effects
are usually short term and treatable. Sometimes the treatment is
simply eliminating the person s exposure to the source of the
pollution, if it can be identified. Symptoms of some diseases,
including asthma, hypersensitivity pneumonitis, and humidifier
fever, may also show up soon after exposure to some indoor air
pollutants.

The likelihood of immediate reactions to indoor air pollutants
depends on several factors. Age and preexisting medical
conditions are two important influences. In other cases, whether
a person reacts to a pollutant depends on individual sensitivity,
which varies tremendously from person to person. Some people can
become sensitized to biological pollutants after repeated
exposures, and it appears that some people can become sensitized
to chemical pollutants as well.

Certain immediate effects are similar to those from colds or
other viral diseases, so it is often difficult to determine if
the symptoms are a result of exposure to indoor air pollution.
For this reason, it is important to pay attention to the time and
place the symptoms occur. If the symptoms fade or go away when a
person is away from the home and return when the person returns,
an effort should be made to identify indoor air sources that may
be possible causes. Some effects may be made worse by an
inadequate supply of outdoor air or from the heating, cooling, or
humidity conditions prevalent in the home.

Other health effects may show up either years after exposure has
occurred or only after long or repeated periods of exposure.
These effects, which include some respiratory diseases, heart
disease, and cancer, can be severely debilitating or fatal. It is
prudent to try to improve the indoor air quality in your home
even if symptoms are not noticeable. More information on
potential health effects from particular indoor air pollutants is
provided in the section, A Look at Source Specific Controls.

While pollutants commonly found in indoor air are responsible for
many harmful effects, there is considerable uncertainty about
what concentrations or periods of exposure are necessary to
produce specific health problems. People also react very
differently to exposure to indoor air pollutants. Further
research is needed to better understand which health effects
occur after exposure to the average pollutant concentrations
found in homes and which occur from the higher concentrations
that occur for short periods of time.

The health effects associated with some indoor air pollutants are
summarized in the chart in the middle of this booklet titled
Reference Guide to Major Indoor Air Pollutants in the Home.

IDENTIFYING AIR QUALITY PROBLEMS

Some health effects can be useful indicators of an indoor air
quality problem, especially if they appear after a person moves
to a new residence, remodels or refurnishes a home, or treats a
home with pesticides. If you think that you have symptoms that
may be related to your home environment, discuss the with your
doctor or your local health department to see if they could be
caused by indoor air pollution. You may also want to consult a
board certified allergist or an occupational medicine specialist
for answers to your questions.

Another way to judge whether your home has or could develop
indoor air problems is to identify potential sources of indoor
air pollution. Although the presence of such sources (see
illustration at the beginning of this booklet) does not
necessarily mean that you have an indoor air quality problem,
being aware of the type and number of potential sources is an
important step toward assessing the air quality in your home.

A third way to decide whether your home may have poor indoor air
quality is to look at your lifestyle and activities. Human
activities can be significant sources of indoor air pollution.
Finally, look for signs of problems with the ventilation in your
home. Signs that can indicate your home may not have enough
ventilation include moisture condensation on windows or walls,
smelly or stuffy air, dirty central heating and air cooling
equipment, and areas where books, shoes, or other items become
moldy. To detect odors in your home, step outside for a few
minutes, and then upon reentering your home, note whether odors
are noticeable.

MEASURING POLLUTANT LEVELS

The federal government recommends that you measure the level of
radon in your home. Without measurements there is no way to tell
whether radon is present because it is a colorless, odorless,
radioactive gas. Inexpensive devices are available for measuring
radon. EPA provides guidance as to risks associated with
different levels of exposure and when the public should consider
corrective action. There are specific mitigation techniques that
have proven effective in reducing levels of radon in the home.
(See Radon section on p. 11 of this booklet for additional
information about testing and controlling radon in homes.)

For pollutants other than radon, measurements are most
appropriate when there are either health symptoms or signs of
poor ventilation and specific sources or pollutants have been
identified as possible causes of indoor air quality problems.
Testing for many pollutants can be expensive. Before monitoring
your home for pollutants besides radon, consult your state or
local health department or professionals who have experience in
solving indoor air quality problems in nonindustrial buildings.

WEATHERIZING YOUR HOME

The federal government recommends that homes be weatherized in
order to reduce the amount of energy needed for heating and
cooling. While weatherization is underway, however, steps should
also be taken to minimize pollution from sources inside the home.
(See Improving the Air Quality in Your Home for recommended
actions.) In addition, residents should be alert to the emergence
of signs of inadequate ventilation, such as stuffy air, moisture
condensation on cold surfaces, or mold and mildew growth.
Additional weatherization measures should not be undertaken until
these problems have been corrected.

Weatherization generally does not cause indoor air problems by
adding new pollutants to the air. (There are a few exceptions,
such as caulking, that can sometimes emit pollutants.) However,
measures such as installing storm windows, weather stripping,
caulking, and blown in wall insulation can reduce the amount of
outdoor air infiltrating into a home. Consequently, after
weatherization, concentrations of indoor air pollutants from
sources inside the home can increase.

THREE BASIC STRATEGIES

Source Control

Usually the most effective way to improve indoor air quality is
to eliminate individual sources of pollution or to reduce their
emissions. Some sources, like those that contain asbestos, can be
sealed or enclosed; others, like gas stoves, can be adjusted to
decrease the amount of emissions. In many cases, source control
is also a more cost efficient approach to protecting indoor air
quality than increasing ventilation because increasing
ventilation can increase energy costs. Specific sources of indoor
air pollution in your home are listed later in this section.

Ventilation Improvements

Another approach to lowering the concentrations of indoor air
pollutants in your home is to increase the amount of outdoor air
coming indoors. Most home heating and cooling systems, including
forced air heating systems, do not mechanically bring fresh air
into the house. Opening windows and doors, operating window or
attic fans, when the weather permits, or running a window air
conditioner with the vent control open increases the outdoor
ventilation rate. Local bathroom or kitchen fans that exhaust
outdoors remove contaminants directly from the room where the fan
is located and also increase the outdoor air ventilation rate.

It is particularly important to take as many of these steps
as possible while you are involved in short-term activities that
can generate high levels of pollutants for example, painting,
paint stripping, heating with kerosene heaters, cooking, or
engaging in maintenance and hobby activities such as welding,
soldering, or sanding. You might also choose to do some of these
activities outdoors, if you can and if weather permits.

Advanced designs of new homes are starting to feature mechanical
systems that bring outdoor air into the home. Some of these
designs include energy efficient heat recovery ventilators (also
known as air-to-air heat exchangers). For more information about
air-to-air heat exchangers, contact the Conservation and
Renewable Energy Inquiry and Referral Service (CAREIRS), PO Box
3048, Merrifield, VA 22116; (800) 5232929.

Air Cleaners

There are many types and sizes of air cleaners on the market,
ranging from relatively inexpensive tabletop models to
sophisticated and expensive whole house systems. Some air
cleaners are highly effective at particle removal, while others,
including most tabletop models, are much less so. Air cleaners
are generally not designed to remove gaseous pollutants.

The effectiveness of an air cleaner depends on how well it
collects pollutants from indoor air (expressed as a percentage
efficiency rate) and how much air it draws through the cleaning
or filtering element (expressed in cubic feet per minute). A very
efficient collector with a low air circulation rate will not be
effective, nor will a cleaner with a high air circulation rate
but a less efficient collector. The long term performance of any
air cleaner depends on maintaining it according to the
manufacturer s directions.

Another important factor in determining the effectiveness of
an air cleaner is the strength of the pollutant source. Tabletop
air cleaners, in particular, may not remove satisfactory amounts
of pollutants from strong nearby sources. People with a
sensitivity to particular sources may find that air cleaners are
helpful only in conjunction with concerted efforts to remove the
source.

Over the past few years, there has been some publicity
suggesting that house plants have been shown to reduce levels of
some chemicals in laboratory experiments. There is currently no
evidence, however, that a reasonable number of houseplants remove
significant quantities of pollutants in homes and offices.
Indoor houseplants should not be over watered because overly damp
soil may promote the growth of microorganisms which can affect
allergic individuals.

At present, EPA does not recommend using air cleaners to
reduce levels of radon and its decay products. The effectiveness
of these devices is uncertain because they only partially remove
the radon decay products and do not diminish the amount of radon
entering the home. EPA plans to do additional research on whether
air cleaners are, or could become, a reliable means of reducing
the health risk from radon. EPA s booklet, Residential Air
Cleaning Devices, provides further information on air cleaning
devices to reduce indoor air pollutants

For most indoor air quality problems in the home, source control
is the most effective solution. This section takes a source by
source look at the most common indoor air pollutants, their
potential health effects, and ways to reduce levels in the home.
(For a summary of the points made in this section, see the chart
in the middle of this booklet titled Reference Guide to Major
Indoor Air Pollutants in the Home. )

RADON

The most common source of indoor radon is uranium in the soil or
rock on which homes are built. As uranium naturally breaks down,
it releases radon gas which is a colorless, odorless, radioactive
gas. Radon gas enters homes through dirt floors, cracks in
concrete walls and floors, floor drains, and sumps. When radon
become strapped in buildings and concentrations build up indoors,
exposure to radon becomes a concern.

Any home may have a radon problem. This means new and old
homes, well sealed and drafty homes, and homes with or without
basements.

Sometimes radon enters the home through well water. In a small
number of homes, the building materials can give off radon, too.
However, building materials rarely cause radon problems by
themselves.

Health Effects of Radon

The predominant health effect associated with exposure to
elevated levels of radon is lung cancer. Research suggests that
swallowing water with high radon levels may pose risks, too,
although these are believed to be much lower than those from
breathing air containing radon. Major health organizations (like
the Centers for Disease Control and Prevention, the American Lung
Association (ALA), and the American Medical Association) agree
with estimates that radon causes thousands of preventable lung
cancer deaths each year. EPA estimates that radon causes about
14,000 deaths per year in the United States however, this number
could range from 7,000 to 30,000 deaths per year. If you smoke
and your home has high radon levels, your risk of lung cancer is
especially high.

Reducing Exposure to Radon in Homes

Measure levels of radon in your home.

You can t see radon, but it s not hard to find out if you have a
radon problem in your home. Testing is easy and should only take
a little of your time.

There are many kinds of inexpensive, do-it-yourself radon
test kits you can get through the mail and in hardware stores and
other retail outlets. Make sure you buy a test kit that has
passed EPA s testing program or is state certified. These kits
will usually display the phrase Meets EPA Requirements. If you
prefer, or if you are buying or selling a home, you can hire a
trained contractor to do the testing for you. The EPA Radon
Measurement Proficiency (RMP) Program evaluates testing
contractors. A contractor who has met EPA s requirements will
carry a special RMP identification card. EPA provides a list of
companies and individual contractors to state radon offices. You
can call your state radon office to obtain a list of qualified
contractors in your area (call 800-SOS-RADON for a list of state
radon offices).

Refer to the EPA guidelines on how to test and interpret your
test results.

You can learn more about radon through EPA s publications, A
Citizen s Guide to Radon: The Guide to Protecting Yourself and
Your Family From Radon and Home Buyer s and Seller s Guide to
Radon, which are available from state radon offices.

Learn about radon reduction methods.

Ways to reduce radon in your home are discussed in EPA s Consumer
s Guide to Radon Reduction. You can get a copy from your state
radon office. There are simple solutions to radon problems in
homes. Thousands of homeowners have already fixed radon
problems. Lowering high radon levels requires technical
knowledge and special skills. You should use a contractor who is
trained to fix radon problems.

The EPA Radon Contractor Proficiency (RCP) Program tests
these contractors. EPA provides a list of RCP contractors to
state radon offices. A contractor who is listed by EPA will
carry a special RCP identification card. A trained RCP
contractor can study the problem in your home and help you pick
the correct treatment method. Check with your state radon office
for names of qualified or state certified radon reduction
contractors in your area.

Stop smoking and discourage smoking in your home.

Scientific evidence indicates that smoking combined with radon is
an especially serious health risk. Stop smoking and lower your
radon level to reduce lung cancer risk.

Treat radon contaminated well water.

While radon in water is not a problem in homes served by most
public water supplies, it has been found in well water. If
you've tested the air in your home and found a radon problem, and
you have a well, contact a lab certified to measure radiation in
water to have your water tested. Radon problems in water can be
readily fixed. Call your state radon office or the EPA Drinking
Water Hotline (8004264791) for more information.

ENVIRONMENTAL TOBACCO SMOKE

Environmental tobacco smoke (ETS) is the mixture of smoke that
comes from the burning end of a cigarette, pipe, or cigar, and
smoke exhaled by the smoker. It is a complex mixture of over
4,000 compounds, more than 40 of which are known to cause cancer
in humans or animals and many of which are strong irritants.
ETS is often referred to as secondhand smoke and exposure to
ETS is often called passive smoking.

Health Effects of Environmental Tobacco Smoke

In 1992, EPA completed a major assessment of the respiratory
health risks of ETS (Respiratory Health Effects of Passive
Smoking: Lung Cancer and Other Disorders EPA/600/690/006F). The
report concludes that exposure to ETS is responsible for
approximately 3,000 lung cancer deaths each year in non-smoking
adults and impairs the respiratory health of hundreds of
thousands of children.

Infants and young children whose parents smoke in their
presence are at increased risk of lower respiratory tract
infections (pneumonia and bronchitis) and are more likely to have
symptoms of respiratory irritation like cough, excess phlegm, and
wheeze. EPA estimates that passive smoking annually causes
between 150,000 and 300,000 lower respiratory tract infections in
infants and children under 18 months of age, resulting in between
7,500 and 15,000 hospitalizations each year. These children may
also have a buildup of fluid in the middle ear, which can lead to
ear infections. Older children who have been exposed to
secondhand smoke may have slightly reduced lung function.

Asthmatic children are especially at risk. EPA estimates that
exposure to secondhand smoke increases the number of episodes and
severity of symptoms in hundreds of thousands of asthmatic
children, and may cause thousands of non-asthmatic children to
develop the disease each year. EPA estimates that between
200,000 and 1,000,000 asthmatic children have their condition
made worse by exposure to secondhand smoke each year.

Exposure to secondhand smoke causes eye, nose, and throat
irritation. It may affect the cardiovascular system and some
studies have linked exposure to secondhand smoke with the onset
of chest pain. For publications about ETS, contact EPA s Indoor
Air Quality Information Clearinghouse (IAQ-INFO), 8004384318.

Reducing Exposure to Environmental Tobacco Smoke

Don t smoke at home or permit others to do so. Ask smokers to
smoke outdoors.

The 1986 Surgeon General s report concluded that physical
separation of smokers and nonsmokers in a common air space, such
as different rooms within the same house, may reduce but will not
eliminate nonsmokers exposure to environmental tobacco smoke.

If smoking indoors cannot be avoided, increase ventilation in
the area where smoking takes place.

Open windows or use exhaust fans. Ventilation, a common method
of reducing exposure to indoor air pollutants, also will reduce
but not eliminate exposure to environmental tobacco smoke.
Because smoking produces such large amounts of pollutants,
natural or mechanical ventilation techniques do not remove them
from the air in your home as quickly as they build up. In
addition, the large increases in ventilation it takes to
significantly reduce exposure to environmental tobacco smoke can
also increase energy costs substantially. Consequently, the most
effective way to reduce exposure to environmental tobacco smoke
in the home is to eliminate smoking there.

Do not smoke if children are present, particularly infants and
toddlers.

Children are particularly susceptible to the effects of passive
smoking. Do not allow baby sitters or others who work in your
home to smoke indoors. Discourage others from smoking around
children. Find out about the smoking policies of the day care
center providers, schools, and other care givers for your
children. The policy should protect children from exposure to
ETS.

BIOLOGICAL CONTAMINANTS

Biological contaminants include bacteria, molds, mildew, viruses,
animal dander and cat saliva, house dust mites, cockroaches, and
pollen. There are many sources of these pollutants. Pollens
originate from plants; viruses are transmitted by people and
animals; bacteria are carried by people, animals, and soil and
plant debris; and household pets are sources of saliva and animal
dander. The protein in urine from rats and mice is a potent
allergen. When it dries, it can become airborne. Contaminated
central air handling systems can become breeding grounds for
mold, mildew, and other sources of biological contaminants and
can then distribute these contaminants through the home.

By controlling the relative humidity level in a home, the
growth of some sources of biologicals can be minimized. A
relative humidity of 3050 percent is generally recommended for
homes. Standing water, water-damaged materials, or wet surfaces
also serve as a breeding ground for molds, mildews, bacteria, and
insects. House dust mites, the source of one of the most powerful
biological allergens, grow in damp, warm environments.

Health Effects From Biological Contaminants

Some biological contaminants trigger allergic reactions,
including hypersensitivity pneumonitis, allergic rhinitis, and
some types of asthma. Infectious illnesses, such as influenza,
measles, and chicken pox are transmitted through the air. Molds
and mildews release disease causing toxins. Symptoms of health
problems caused by biological pollutants include sneezing, watery
eyes, coughing, shortness of breath, dizziness, lethargy, fever,
and digestive problems.

Allergic reactions occur only after repeated exposure to a
specific biological allergen. However, that reaction may occur
immediately upon re-exposure or after multiple exposures over
time. As a result, people who have noticed only mild allergic
reactions, or no reactions at all, may suddenly find themselves
very sensitive to particular allergens.

Some diseases, like humidifier fever, are associated with
exposure to toxins from microorganisms that can grow in large
building ventilation systems. However, these diseases can also be
traced to microorganisms that grow in home heating and cooling
systems and humidifiers. Children, elderly people, and people
with breathing problems, allergies, and lung diseases are
particularly susceptible to disease causing biological agents in
the indoor air.

Reducing Exposure to Biological Contaminants

Install and use exhaust fans that are vented to the outdoors in
kitchens and bathrooms and vent clothes dryers outdoors.

These actions can eliminate much of the moisture that builds up
from everyday activities. There are exhaust fans on the market
that produce little noise, an important consideration for some
people. Another benefit to using kitchen and bathroom exhaust
fans is that they can reduce levels of organic pollutants that
vaporize from hot water used in showers and dishwashers.

Ventilate the attic and crawl spaces to prevent moisture
buildup.

Keeping humidity levels in these areas below 50 percent can
prevent water condensation on building materials.

If using cool mist or ultrasonic humidifiers, clean appliances
according to manufacturer s instructions and refill with fresh
water daily.

Because these humidifiers can become breeding grounds for
biological contaminants, they have the potential for causing
diseases such as hypersensitivity pneumonitis and humidifier
fever. Evaporation trays in air conditioners, dehumidifiers, and
refrigerators should also be cleaned frequently.

Thoroughly clean and dry water-damaged carpets and building
materials (within 24 hours if possible) or consider removal and
replacement.

Water-damaged carpets and building materials can harbor mold and
bacteria. It is very difficult to completely rid such materials
of biological contaminants.

Keep the house clean. House dust mites, pollens, animal dander,
and other allergy causing agents can be reduced, although not
eliminated, through regular cleaning.

People who are allergic to these pollutants should use allergen
proof mattress encasements, wash bedding in hot (130 F) water,
and avoid room furnishings that accumulate dust, especially if
they cannot be washed in hot water. Allergic individuals should
also leave the house while it is being vacuumed because vacuuming
can actually increase airborne levels of mite allergens and other
biological contaminants. Using central vacuum systems that are
vented to the outdoors or vacuums with high efficiency filters
may also be of help.

Take steps to minimize biological pollutants in basements.

Clean and disinfect the basement floor drain regularly. Do not
finish a basement below ground level unless all water leaks are
patched and outdoor ventilation and adequate heat to prevent
condensation are provided. Operate a dehumidifier in the basement
if needed to keep relative humidity levels between 30 50 percent.

To learn more about biological pollutants, read Biological
Pollutants in Your Home issued by the U.S. Consumer Product
Safety Commission and the American Lung Association. For contact
information, see the section, Where to Go For Additional
Information.

STOVES, HEATERS, FIREPLACES, AND CHIMNEYS

In addition to environmental tobacco smoke, other sources of
combustion products are unvented kerosene and gas space heaters,
wood stoves, fireplaces, and gas stoves. The major pollutants
released are carbon monoxide, nitrogen dioxide, and particles.
Unvented kerosene heaters may also generate acid aerosols.

Combustion gases and particles also come from chimneys and
flues that are improperly installed or maintained and cracked
furnace heat exchangers. Pollutants from fireplaces and wood
stoves with no dedicated outdoor air supply can be back drafted
from the chimney into the living space, particularly in
weatherized homes.

Health Effects of Combustion Products

Carbon monoxide is a colorless, odorless gas that interferes with
the delivery of oxygen throughout the body. At high
concentrations it can cause unconsciousness and death. Lower
concentrations can cause a range of symptoms from headaches,
dizziness, weakness, nausea, confusion, and disorientation, to
fatigue in healthy people and episodes of increased chest pain in
people with chronic heart disease. The symptoms of carbon
monoxide poisoning are sometimes confused with the flu or food
poisoning. Fetuses, infants, elderly people, and people with
anemia or with a history of heart or respiratory disease can be
especially sensitive to carbon monoxide exposures.

Nitrogen dioxide is a colorless, odorless gas that irritates
the mucous membranes in the eye, nose, and throat and causes
shortness of breath after exposure to high concentrations. There
is evidence that high concentrations or continued exposure to low
levels of nitrogen dioxide increases the risk of respiratory
infection; there is also evidence from animal studies that
repeated exposures to elevated nitrogen dioxide levels may lead,
or contribute, to the development of lung disease such as
emphysema. People at particular risk from exposure to nitrogen
dioxide include children and individuals with asthma and other
respiratory diseases.

Particles, released when fuels are incompletely burned, can lodge
in the lungs and irritate or damage lung tissue. A number of
pollutants, including radon and benzo(a)pyrene, both of which can
cause cancer, attach to small particles that are inhaled and then
carried deep into the lung.

Reducing Exposure to Combustion Products in Homes

Take special precautions when operating fuel burning unvented
space heaters.

Consider potential effects of indoor air pollution if you use an
unvented kerosene or gas space heater. Follow the manufacturer s
directions, especially instructions on the proper fuel and
keeping the heater properly adjusted. A persistent yellow tipped
flame is generally an indicator of maladjustment and increased
pollutant emissions. While a space heater is in use, open a door
from the room where the heater is located to the rest of the
house and open a window slightly.

Install and use exhaust fans over gas cooking stoves and ranges
and keep the burners properly adjusted.

Using a stove hood with a fan vented to the outdoors greatly
reduces exposure to pollutants during cooking. Improper
adjustment, often indicated by a persistent yellow tipped flame,
causes increased pollutant emissions. Ask your gas company to
adjust the burner so that the flame tip is blue. If you purchase
a new gas stove or range, consider buying one with pilotless
ignition because it does not have a pilot light that burns
continuously. Never use a gas stove to heat your home. Always
make certain the flue in your gas fireplace is open when the
fireplace is in use.

Keep wood stove emissions to a minimum. Choose properly sized
new stoves that are certified as meeting EPA emission standards.

Make certain that doors in old wood stoves are tight fitting. Use
aged or cured (dried) wood only and follow the manufacturer s
directions for starting, stoking, and putting out the fire in
wood stoves. Chemicals are used to pressure treat wood; such wood
should never be burned indoors. (Because some old gaskets in wood
stove doors contain asbestos, when replacing gaskets refer to the
instructions in the CPSC, ALA, and EPA booklet, Asbestos in Your
Home, to avoid creating an asbestos problem. New gaskets are made
of fiberglass.)

Have central air handling systems, including furnaces, flues,
and chimneys, inspected annually and promptly repair cracks or
damaged parts.

Blocked, leaking, or damaged chimneys or flues release harmful
combustion gases and particles and even fatal concentrations of
carbon monoxide. Strictly follow all service and maintenance
procedures recommended by the manufacturer, including those that
tell you how frequently to change the filter. If manufacturer s
instructions are not readily available, change filters once every
month or two during periods of use. Proper maintenance is
important even for new furnaces because they can also corrode and
leak combustion gases, including carbon monoxide. Read the
booklet What You Should Know About Combustion Appliances and
Indoor Air Pollution to learn more about combustion pollutants.
The booklet is available by contacting CPSC, EPA s IAQ INFO
Clearinghouse, or your local ALA. (See Where to Go for
Additional Information for contact information.)

HOUSEHOLD PRODUCTS

Organic chemicals are widely used as ingredients in household
products. Paints, varnishes, and wax all contain organic
solvents, as do many cleaning, disinfecting, cosmetic,
decreasing, and hobby products. Fuels are made up of organic
chemicals. All of these products can release organic compounds
while you are using them, and, to some degree, when they are
stored.

EPA s Total Exposure Assessment Methodology (TEAM) studies
found levels of about a dozen common organic pollutants to be 2
to 5 times higher inside homes than outside, regardless of
whether the homes were located in rural or highly industrial
areas. Additional TEAM studies indicate that while people are
using products containing organic chemicals, they can expose
themselves and others to very high pollutant levels, and elevated
concentrations can persist in the air long after the activity is
completed.

Health Effects of Household Chemicals

The ability of organic chemicals to cause health effects varies
greatly from those that are highly toxic, to those with no
known health effect. As with other pollutants, the extent and
nature of the health effect will depend on many factors including
level of exposure and length of time exposed. Eye and
respiratory tract irritation, headaches, dizziness, visual
disorders, and memory impairment are among the immediate symptoms
that some people have experienced soon after exposure to some
organics. At present, not much is known about what health effects
occur from the levels of organics usually found in homes. Many
organic compounds are known to cause cancer in animals; some are
suspected of causing, or are known to cause, cancer in humans.

Reducing Exposure to Household Chemicals

Follow label instructions carefully.

Potentially hazardous products often have warnings aimed at
reducing exposure of the user. For example, if a label says to
use the product in a well ventilated area, go outdoors or in
areas equipped with an exhaust fan to use it. Otherwise, open up
windows to provide the maximum amount of outdoor air possible.

Throw away partially full containers of old or unneeded
chemicals safely.

Because gases can leak even from closed containers, this single
step could help lower concentrations of organic chemicals in your
home. (Be sure that materials you decide to keep are stored not
only in a well ventilated area but are also safely out of reach
of children.) Do not simply toss these unwanted products in the
garbage can. Find out if your local government or any
organization in your community sponsors special days for the
collection of toxic household wastes. If such days are available,
use them to dispose of the unwanted containers safely. If no such
collection days are available, think about organizing one.

Buy limited quantities.

If you use products only occasionally or seasonally, such as
paints, paint strippers, and kerosene for space heaters or
gasoline for lawn mowers, buy only as much as you will use right
away.

Keep exposure to emissions from products containing methylene
chloride to a minimum.

Consumer products that contain methylene chloride include paint
strippers, adhesive removers, and aerosol spray paints. Methylene
chloride is known to cause cancer in animals. Also, methylene
chloride is converted to carbon monoxide in the body and can
cause symptoms associated with exposure to carbon monoxide.
Carefully read the labels containing health hazard information
and cautions on the proper use of these products. Use products
that contain methylene chloride outdoors when possible; use
indoors only if the area is well ventilated.

Keep exposure to benzene to a minimum.

Benzene is a known human carcinogen. The main indoor sources of
this chemical are environmental tobacco smoke, stored fuels and
paint supplies, and automobile emissions in attached garages.
Actions that will reduce benzene exposure include eliminating
smoking within the home, providing for maximum ventilation during
painting, and discarding paint supplies and special fuels that
will not be used immediately.

Keep exposure to perchloroethylene emissions from newly dry
cleaned materials to a minimum.

Perchloroethylene is the chemical most widely used in dry
cleaning. In laboratory studies, it has been shown to cause
cancer in animals. Recent studies indicate that people breathe
low levels of this chemical both in homes where dry cleaned goods
are stored and as they wear dry cleaned clothing. Dry cleaners
recapture the perchloroethylene during the dry cleaning process
so they can save money by re using it, and they remove more of
the chemical during the pressing and finishing processes. Some
dry cleaners, however, do not remove as much perchloroethylene as
possible all of the time. Taking steps to minimize your exposure
to this chemical is prudent. If dry cleaned goods have a strong
chemical odor when you pick them up, do not accept them until
they have been properly dried. If goods with a chemical odor are
returned to you on subsequent visits, try a different dry
cleaner.

FORMALDEHYDE

Formaldehyde is an important chemical used widely by industry to
manufacture building materials and numerous household products.
It is also a byproduct of combustion and certain other natural
processes. Thus, it may be present in substantial concentrations
both indoors and outdoors.

Sources of formaldehyde in the home include building
materials, smoking, household products, and the use of unvented,
fuel burning appliances, like gas stoves or kerosene space
heaters. Formaldehyde, by itself or in combination with other
chemicals, serves a number of purposes in manufactured products.
For example, it is used to add permanent press qualities to
clothing and draperies, as a component of glues and adhesives,
and as a preservative in some paints and coating products.

In homes, the most significant sources of formaldehyde are likely
to be pressed wood products made using adhesives that contain
ureaformaldehyde (UF) resins. Pressed wood products made for
indoor use include: particle board (used as sub flooring and
shelving and in cabinetry and furniture); hardwood plywood
paneling (used for decorative wall covering and used in cabinets
and furniture); and medium density fiberboard (used for drawer
fronts, cabinets, and furniture tops). Medium density fiberboard
contains a higher resin to wood ratio than any other UF pressed
wood product and is generally recognized as being the highest
formaldehyde emitting pressed wood product.

Other pressed wood products, such as softwood plywood and flake
or oriented strand board, are produced for exterior construction
use and contain the dark, or red/black colored phenolformaldehyde
(PF) resin. Although formaldehyde is present in both types of
resins, pressed woods that contain PF resin generally emit
formaldehyde at considerably lower rates than those containing UF
resin.

Since 1985, the Department of Housing and Urban Development (HUD)
has permitted only the use of plywood and particle board that
conform to specified formaldehyde emission limits in the
construction of prefabricated and mobile homes. In the past, some
of these homes had elevated levels of formaldehyde because of the
large amount of high emitting pressed wood products used in their
construction and because of their relatively small interior
space.

The rate at which products like pressed wood or textiles release
formaldehyde can change. Formaldehyde emissions will generally
decrease as products age. When the products are new, high indoor
temperatures or humidity can cause increased release of
formaldehyde from these products.

During the 1970s, many homeowners had ureaformaldehyde foam

insulation (UFFI) installed in the wall cavities of their homes
as an energy conservation measure. However, many of these homes
were found to have relatively high indoor concentrations of
formaldehyde soon after the UFFI installation. Few homes are now
being insulated with this product. Studies show that formaldehyde emissions from UFFI decline with time;
therefore, homes in which UFFI was installed many years ago are
unlikely to have high levels of formaldehyde now.

Health Effects of Formaldehyde

Formaldehyde, a colorless, pungent smelling gas, can cause watery
eyes, burning sensations in the eyes and throat, nausea, and
difficulty in breathing in some humans exposed at elevated levels
(above 0.1 parts per million). High concentrations may trigger
attacks in people with asthma. There is evidence that some people
can develop a sensitivity to formaldehyde. It has also been shown
to cause cancer in animals and may cause cancer in humans.

Reducing Exposure to Formaldehyde in Homes

Ask about the formaldehyde content of pressed wood products,
including building materials, cabinetry, and furniture before you
purchase them.

If you experience adverse reactions to formaldehyde, you may want
to avoid the use of pressed wood products and other formaldehyde
emitting goods. Even if you do not experience such reactions, you
may wish to reduce your exposure as much as possible by
purchasing exterior grade products, which emit less formaldehyde.
For further information on formaldehyde and consumer products,
call the EPA Toxic Substance Control Act (TSCA) assistance line
(2025541404).

Some studies suggest that coating pressed wood products with
polyurethane may reduce formaldehyde emissions for some period of
time. To be effective, any such coating must cover all surfaces
and edges and remain intact. Increase the ventilation and
carefully follow the manufacturer s instructions while applying
these coatings. (If you are sensitive to formaldehyde, check the
label contents before purchasing coating products to avoid buying
products that contain formaldehyde, as they will emit the
chemical for a short time after application.)

Maintain moderate temperature and humidity levels and provide
adequate ventilation.

The rate at which formaldehyde is released is accelerated by heat
and may also depend somewhat on the humidity level. Therefore,
the use of dehumidifiers and air conditioning to control humidity
and to maintain a moderate temperature can help reduce
formaldehyde emissions. (Drain and clean dehumidifier collection
trays frequently so that they do not become a breeding ground for
microorganisms.) Increasing the rate of ventilation in your home
will also help in reducing formaldehyde levels.

PESTICIDES

According to a recent survey, 75 percent of U.S. households
used at least one pesticide product indoors during the past year.
Products used most often are insecticides and disinfectants.
Another study suggests that 80 90 percent of most people s
exposure to pesticides occurs indoors and that measurable
levels of up to a dozen pesticides have been found in the air
inside homes. The amount of pesticides found in homes appears to
be greater than can be explained by recent pesticide use in those
households; other possible sources include contaminated soil or
dust that floats or is tracked in from outside, stored pesticide
containers, and household surfaces that collect and then release
the pesticides. Pesticides used in and around the home include
products to control insects (insecticides), termites
(termiticides), rodents (rodenticides), fungi (fungicides), and
microbes (disinfectants). They are sold as sprays, liquids,
sticks, powders, crystals, balls, and foggers.

In 1990, the American Association of Poison Control Centers
reported that some 79,000 children were involved in common
household pesticide poisonings or exposures. In households with
children under five years old, almost one half stored at least
one pesticide product within reach of children.

EPA registers pesticides for use and requires manufacturers to
put information on the label about when and how to use the
pesticide. It is important to remember that the "cide" in
pesticides means to kill. These products can be dangerous if
not used properly.

In addition to the active ingredient, pesticides are also made up
of ingredients that are used to carry the active agent. These
carrier agents are called "inerts" in pesticides because they are
not toxic to the targeted pest; nevertheless, some inerts are
capable of causing health problems.

Health Effects From Pesticides

Both the active and inert ingredients in pesticides can be
organic compounds; therefore, both could add to the levels of
airborne organics inside homes. Both types of ingredients can
case the effects discussed in this booklet under Household
Products. However, as with other household products, there is
insufficient understanding at present about what pesticide
concentrations are necessary to produce these effects.

Exposure to high levels of cyclodiene pesticides, commonly
associated with misapplication, has produced various symptoms,
including headaches, dizziness, muscle twitching, weakness,
tingling sensations, and nausea. In addition, EPA is concerned
that cyclodienes might cause long term damage to the liver and
the central nervous system, as well as an increased risk of
cancer.

There is no further sale or commercial use permitted for the
following cyclodiene or related pesticides: chlordane, aldrin,
dieldrin, and heptachlor. The only exception is the use of
heptachlor by utility companies to control fire ants in
underground cable boxes.

Reducing Exposure to Pesticides in Homes

Read the label and follow the directions. It is illegal to use
any pesticide in any manner inconsistent with the directions on
its label.

Unless you have had special training and are certified, never use
a pesticide that is restricted to use by state certified pest
control operators. Such pesticides are simply too dangerous for
application by a non certified person. Use only the pesticides
approved for use by the general public and then only in
recommended amounts; increasing the amount does not offer more
protection against pests and can be harmful to you and your
plants and pets.

Ventilate the area well after pesticide use.

Mix or dilute pesticides outdoors or in a well ventilated area
and only in the amounts that will be immediately needed. If
possible, take plants and pets outside when applying pesticides
to them.

Use nonchemical methods of pest control when possible.

Since pesticides can be found far from the site of their original
application, it is prudent to reduce the use of chemical
pesticides outdoors as well as indoors. Depending on the site and
pest to be controlled, one or more of the following steps can be
effective: use of biological pesticides, such as Bacillus
thuringiensis, for the control of gypsy moths; selection of
disease resistant plants; and frequent washing of indoor plants
and pets. Termite damage can be reduced or prevented by making
certain that wooden building materials do not come into direct
contact with the soil and by storing firewood away from the home.
By appropriately fertilizing, watering, and aerating lawns, the
need for chemical pesticide treatments of lawns can be
dramatically reduced.

If you decide to use a pest control company, choose one
carefully.

Ask for an inspection of your home and get a written control
program for evaluation before you sign a contract. The control
program should list specific names of pests to be controlled and
chemicals to be used; it should also reflect any of your safety
concerns. Insist on a proven record of competence and customer
satisfaction.

Dispose of unwanted pesticides safely.

If you have unused or partially used pesticide containers you
want to get rid of, dispose of them according to the directions
on the label or on special household hazardous waste collection
days. If there are no such collection days in your community,
work with others to organize them.

Keep exposure to moth repellents to a minimum.

One pesticide often found in the home is paradichlorobenzene, a
commonly used active ingredient in moth repellents. This chemical
is known to cause cancer in animals, but substantial scientific
uncertainty exists over the effects, if any, of long term human
exposure to paradichlorobenzene. EPA requires that products
containing paradichlorobenzene bear warnings such as avoid
breathing vapors to warn users of potential short term toxic
effects. Where possible, paradichlorobenzene, and items to be
protected against moths, should be placed in trunks or other
containers that can be stored in areas that are separately
ventilated from the home, such as attics and detached garages.
Paradichlorobenzene is also the key active ingredient in many air
fresheners (in fact, some labels for moth repellents recommend
that these same products be used as air fresheners or
deodorants). Proper ventilation and basic household cleanliness
will go a long way toward preventing unpleasant odors.

Call the National Pesticide Telecommunications Network (NPTN).

EPA sponsors the NPTN (800-858-PEST) to answer your questions
about pesticides and to provide selected EPA publications on
pesticides.

ASBESTOS

Asbestos is a mineral fiber that has been used commonly in a
variety of building construction materials for insulation and as
a fire retardant. EPA and CPSC have banned several asbestos
products. Manufacturers have also voluntarily limited uses of
asbestos. Today, asbestos is most commonly found in older homes,
in pipe and furnace insulation materials, asbestos shingles, mill
board, textured paints and other coating materials, and floor
tiles.

Elevated concentrations of airborne asbestos can occur after
asbestos containing materials are disturbed by cutting, sanding
or other remodeling activities. Improper attempts to remove these
materials can release asbestos fibers into the air in homes,
increasing asbestos levels and endangering people living in those
homes.

Health Effects of Asbestos

The most dangerous asbestos fibers are too small to be visible.
After they are inhaled, they can remain and accumulate in the
lungs. Asbestos can cause lung cancer, mesothelioma (a cancer of
the chest and abdominal linings), and asbestosis (irreversible
lung scarring that can be fatal). Symptoms of these diseases do
not show up until many years after exposure began. Most people
with asbestos related diseases were exposed to elevated
concentrations on the job; some developed disease from exposure
to clothing and equipment brought home from job sites.

Reducing Exposure to Asbestos in Homes

Learn how asbestos problems are created in homes. Read the
booklet, Asbestos in Your Home, issued by CPSC, the ALA, and EPA.


To contact these organizations, see the section, Where to Go For
More Information.

If you think your home may have asbestos, don t panic!

Usually it is best to leave asbestos material that is in good
condition alone. Generally, material in good condition will not
release asbestos fiber. There is no danger unless fibers are
released and inhaled into the lungs.

Do not cut, rip, or sand asbestos containing materials.

Leave undamaged materials alone and, to the extent possible,
prevent them from being damaged, disturbed, or touched.
Periodically inspect for damage or deterioration. Discard damaged
or worn asbestos gloves, stove top pads, or ironing board
covers. Check with local health, environmental, or other
appropriate officials to find out about proper handling and
disposal procedures.

If asbestos material is more than slightly damaged, or if
you are going to make changes in your home that might disturb it,
repair or removal by a professional is needed. Before you have
your house remodeled, find out whether asbestos materials are
present.

When you need to remove or clean up asbestos, use a
professionally trained contractor.

Select a contractor only after careful discussion of the problems
in your home and the steps the contractor will take to clean up
or remove them. Consider the option of sealing off the materials
instead of removing them.

Call EPA s TSCA assistance line (2025541404) to find out
whether your state has a training and certification program for
asbestos removal contractors and for information on EPA s
asbestos programs.

LEAD

Lead has long been recognized as a harmful environmental
pollutant. In late 1991, the Secretary of the Department of
Health and Human Services called lead the number one
environmental threat to the health of children in the United
States. There are many ways in which humans are exposed to lead:
through air, drinking water, food, contaminated soil,
deteriorating paint, and dust. Airborne lead enters the body when
an individual breathes or swallows lead particles or dust once it
has settled. Before it was known how harmful lead could be, it
was used in paint, gasoline, water pipes, and many other
products.

Old lead based paint is the most significant source of lead
exposure in the U.S. today. Harmful exposures to lead can be
created when lead based paint is improperly removed from surfaces
by dry scraping, sanding, or open flame burning. High
concentrations of airborne lead particles in homes can also
result from lead dust from outdoor sources, including
contaminated soil tracked inside, and use of lead in certain
indoor activities such as soldering and stained glass making.

Health Effects of Exposure to Lead

Lead affects practically all systems within the body. At high
levels it can cause convulsions, coma, and even death. Lower
levels of lead can adversely affect the brain, central nervous
system, blood cells, and kidneys.

The effects of lead exposure on fetuses and young children
can be severe. They include delays in physical and mental
development, lower IQ levels, shortened attention spans, and
increased behavioral problems. Fetuses, infants, and children
are more vulnerable to lead exposure than adults since lead is
more easily absorbed into growing bodies, and the tissues of
small children are more sensitive to the damaging effects of
lead. Children may have higher exposures since they are more
likely to get lead dust on their hands and then put their fingers
or other lead contaminated objects into their mouths.

Get your child tested for lead exposure. To find out where to do
this, call your doctor or local health clinic. For more
information on health effects, get a copy of the Centers for
Disease Control s, Preventing Lead Poisoning in Young Children
(October 1991).

Ways to Reduce Exposure to Lead

Keep areas where children play as dust free and clean as
possible.

Mop floors and wipe window ledges and chewable surfaces such as
cribs with a solution of powdered automatic dishwasher detergent
in warm water. (Dishwasher detergents are recommended because of
their high content of phosphate.) Most multipurpose cleaners
will not remove lead in ordinary dust. Wash toys and stuffed
animals regularly. Make sure that children wash their hands
before meals, nap time, and bedtime.

Reduce the risk from lead based paint.

Most homes built before 1960 contain heavily leaded paint. Some
homes built as recently as 1978 may also contain lead paint. This
paint could be on window frames, walls, the outside of homes, or
other surfaces. Do not burn painted wood since it may contain
lead.

Leave lead based paint undisturbed if it is in good condition do
not sand or burn off paint that may contain lead.

Lead paint in good condition is usually not a problem except in
places where painted surfaces rub against each other and create
dust (for example, opening a window).

Do not remove lead paint yourself.

Individuals have been poisoned by scraping or sanding lead paint
because these activities generate large amounts of lead dust.
Consult your state health or housing department for suggestions
on which private laboratories or public agencies may be able to
help test your home for lead in paint. Home test kits cannot
detect small amounts of lead under some conditions. Hire a
person with special training for correcting lead paint problems
to remove lead based paint. Occupants, especially children and
pregnant women, should leave the building until all work is
finished and cleanup is done.

For additional information dealing with lead based paint
abatement contact the Department of Housing and Urban Development
for the following two documents: Comprehensive and Workable Plan
for the Abatement of Lead Based Paint in Privately Owned Housing:
Report to Congress (December 7, 1990) and Lead Based Paint:
Interim Guidelines for Hazard Identification and Abatement in
Public and Indian Housing (September 1990).

Do not bring lead dust into the home.

If you work in construction, demolition, painting, with
batteries, in a radiator repair shop or lead factory, or your
hobby involves lead, you may unknowingly bring lead into your
home on your hands or clothes. You may also be tracking in lead
from soil around your home. Soil very close to homes may be
contaminated from lead paint on the outside of the building.
Soil by roads and highways may be contaminated from years of
exhaust fumes from cars and trucks that used leaded gas. Use door
mats to wipe your feet before entering the home. If you work with
lead in your job or a hobby, change your clothes before you go
home and wash these clothes separately. Encourage your children
to play in sand and grassy areas instead of dirt which sticks to
fingers and toys. Try to keep your children from eating dirt,
and make sure they wash their hands when they come inside.

Find out about lead in drinking water.

Most well and city water does not usually contain lead. Water
usually picks up lead inside the home from household plumbing
that is made with lead materials. The only way to know if there
is lead in drinking water is to have it tested. Contact the
local health department or the water supplier to find out how to
get the water tested. Send for the EPA pamphlet, Lead and Your
Drinking Water, for more information about what you can do if you
have lead in your drinking water. Call EPA s Safe Drinking Water
Hotline (8004264791) for more information.

Eat right.

A child who gets enough iron and calcium will absorb less lead.
Foods rich in iron include eggs, red meats, and beans. Dairy
products are high in calcium. Do not store food or liquid in
lead crystal glassware or imported or old pottery. If you reuse
old plastic bags to store or carry food, keep the printing on the
outside of the bag.

You can get a brochure, Lead Poisoning and Your Children,
and more information by calling the National Lead Information
Center, 800-LEAD-FYI.

Building a new home provides the opportunity for preventing
indoor air problems. However, it can result in exposure to
higher levels of indoor air contaminants if careful attention
is not given to potential pollution sources and the air exchange
rate.

Express your concerns about indoor air quality to your
architect or builder and enlist his or her cooperation in taking
measures to provide good indoor air quality. Talk both about
purchasing building materials and furnishings that are low
emitting and about providing an adequate amount of ventilation.

The American Society of Heating, Refrigerating, and Air
Conditioning Engineers recommends a ventilation rate of 0.35 ach
(air changes per hour) for new homes, and some new homes are
built to even tighter specifications. Particular care should be
given in such homes to preventing the buildup of indoor air
pollutants to high levels.

Here are a few important actions that can make a difference:

Use radon resistant construction techniques.

Obtain a copy of the EPA booklet, Radon Resistant Construction
Techniques for Residential Construction, from your state radon
office or health agency, your state homebuilders association, or
your EPA regional office.

Choose building materials and furnishings that will keep indoor
air pollution to a minimum.

There are many actions a homeowner can take to select products
that will prevent indoor air problems from occurring a couple of
them are mentioned here. First, use exterior grade pressed wood
products made with phenolformaldehyde resin in floors, cabinetry,
and wall surfaces. Or, as an alternative, consider using solid
wood products. Secondly, if you plan to install wall to wall
carpet on concrete in contact with the ground, especially
concrete in basements, make sure that an effective moisture
barrier is installed prior to installing the carpet. Do not
permanently adhere carpet to concrete with adhesives so that the
carpet can be removed if it becomes wet.

Provide proper drainage and seal foundations in new
construction.

Air that enters the home through the foundation can contain more
moisture than is generated from all occupant activities.

Become familiar with mechanical ventilation systems and consider
installing one.

Advanced designs of new homes are starting to feature mechanical
systems that bring outdoor air into the home. Some of these
designs include energy efficient heat recovery ventilators (also
known as air to air heat exchangers).

Ensure that combustion appliances, including furnaces,
fireplaces, wood stoves, and heaters, are properly vented and
receive enough supply air.

Combustion gases, including carbon monoxide, and particles can be
back drafted from the chimney or flue into the living space if
the combustion appliance is not properly vented or does not
receive enough supply air. Back drafting can be a particular
problem in weatherized or tightly constructed homes. Installing
a dedicated outdoor air supply for the combustion appliance can
help prevent back drafting.

Indoor air quality problems are not limited to homes. In fact,
many office buildings have significant air pollution sources.
Some of these buildings may be inadequately ventilated. For
example, mechanical ventilation systems may not be designed or
operated to provide adequate amounts of outdoor air. Finally,
people generally have less control over the indoor environment in
their offices than they do in their homes. As a result, there
has been an increase in the incidence of reported health
problems.

HEALTH EFFECTS

A number of well identified illnesses, such as Legionnaire s
disease, asthma, hypersensitivity pneumonitis, and humidifier
fever, have been directly traced to specific building problems.
These are called building related illnesses. Most of these
diseases can be treated nevertheless, some pose serious risks.

Sometimes, however, building occupants experience symptoms
that do not fit the pattern of any particular illness and are
difficult to trace to any specific source. This phenomenon has
been labeled sick building syndrome. People may complain of one
or more of the following symptoms: dry or burning mucous
membranes in the nose, eyes, and throat; sneezing; stuffy or
runny nose; fatigue or lethargy; headache; dizziness; nausea;
irritability an forgetfulness. Poor lighting, noise, vibration,
thermal discomfort, and psychological stress may also cause, or
contribute to, these symptoms.

There is no single manner in which these health problems appear.
In some cases, problems begin as workers enter their offices and
diminish as workers leave; other times, symptoms continue until
the illness is treated. Sometimes there are outbreaks of illness
among many workers in a single building; in other cases, health
symptoms show up only in individual workers.

In the opinion of some World Health Organization experts, up to
30 percent of new or remodeled commercial buildings may have
unusually high rates of health and comfort complaints from
occupants that may potentially be related to indoor air quality.

WHAT CAUSES PROBLEMS?

Three major reasons for poor indoor air quality in office
buildings are the presence of indoor air pollution sources;
poorly designed, maintained, or operated ventilation systems; and
uses of the building that were unanticipated or poorly planned
for when the building was designed or renovated.

Sources of Office Air Pollution

As with homes, the most important factor influencing indoor air
quality is the presence of pollutant sources. Commonly found
office pollutants and their sources include environmental tobacco
smoke; asbestos from insulating and fire retardant building
supplies; formaldehyde from pressed wood products; other organics
from building materials, carpet, and other office furnishings,
cleaning materials and activities, rest room air fresheners,
paints, adhesives, copying machines, and photography and print
shops; biological contaminants from dirty ventilation systems or
water damaged walls, ceilings, and carpets; and pesticides from
pest management practices.

Ventilation Systems

Mechanical ventilation systems in large buildings are designed
and operated not only to heat and cool the air, but also to draw
in and circulate outdoor air. If they are poorly designed,
operated, or maintained, however, ventilation systems can
contribute to indoor air problems in several ways.

For example, problems arise when, in an effort to save
energy, ventilation systems are not used to bring in adequate
amounts of outdoor air. Inadequate ventilation also occurs if the
air supply and return vents within each room are blocked or
placed in such a way that outdoor air does not actually reach the
breathing zone of building occupants. Improperly located outdoor
air intake vents can also bring in air contaminated with
automobile and truck exhaust, boiler emissions, fumes from
dumpsters, or air vented from rest rooms. Finally, ventilation
systems can be a source of indoor pollution themselves by
spreading biological contaminants that have multiplied in cooling
towers, humidifiers, dehumidifiers, air conditioners, or the
inside surfaces of ventilation duct work.

Use of the Building

Indoor air pollutants can be circulated from portions of the
building used for specialized purposes, such as restaurants,
print shops, and dry cleaning stores, into offices in the same
building. Carbon monoxide and other components of automobile
exhaust can be drawn from underground parking garages through
stairwells and elevator shafts into office spaces.

In addition, buildings originally designed for one purpose
may end up being converted to use as office space. If not
properly modified during building renovations, the room
partitions and ventilation system can contribute to indoor air
quality problems by restricting air recirculation or by providing
an inadequate supply of outdoor air.

WHAT TO DO IF YOU SUSPECT A PROBLEM

If you or others at your office are experiencing health or
comfort problems that you suspect may be caused by indoor air
pollution, you can do the following:

Talk with other workers, your supervisor, and union
representatives to see if the problems are being experienced by
others and urge that a record of reported health complaints be
kept by management, if one has not already been established.

Talk with your own physician and report your problems to the
company physician, nurse, or health and safety officer.

Call your state or local health department or air pollution
control agency to talk over the symptoms and possible causes.

Encourage building management to obtain a copy of Building Air
Quality: A Guide for Building Owners and Facility Managers.
Building Air Quality (BAQ) is simply written, yet provides
comprehensive information for identifying, correcting, and
preventing indoor air quality problems. BAQ also provides
supporting information such as when and how to select outside
technical assistance, how to communicate with others regarding
indoor air issues, and where to find additional sources of
information. BAQ is available for $24 from U.S. GPO,
Superintendent of Documents, P.O. Box 371954, Pittsburgh, PA
152507954; stock #055000003904.

Frequently, indoor air quality problems in large commercial
buildings cannot be effectively identified or remedied without a
comprehensive building investigation. These investigations may
start with written questionnaires and telephone consultations in
which building investigators assess the history of occupant
symptoms and building operation procedures. In some cases, these
inquiries may quickly uncover the problem and on site visits are
unnecessary.

More often, however, investigators will need to come to the
building to conduct personal interviews with occupants, to look
for possible sources of the problems, and to inspect the design
and operation of the ventilation system and other building
features. Because taking measurements of pollutants at the very
low levels often found in office buildings is expensive and may
not yield information readily useful in identifying problem
sources, investigators may not take many measurements. The
process of solving indoor air quality problems that result in
health and comfort complaints can be a slow one, involving
several trial solutions before successful remedial actions are
identified.

If a professional company is hired to conduct a building
investigation, select a company on the basis of its experience in
identifying and solving indoor air quality problems in
nonindustrial buildings.

Work with others to establish a smoking policy that eliminates
involuntary nonsmoker exposure to environmental tobacco smoke.

Call the National Institute for Occupational Safety and Health
(NIOSH) for information on obtaining a health hazard evaluation
of your office (800-35-N-EACH), or contact the Occupational
Safety and Health Administration, (202) 2198151.

Federal Information Services

Federal agencies with indoor air quality information may be
contacted as follows:

U.S. Environmental Protection Agency (EPA)
Public Information Center
401 M St., SW
Washington, DC 20460
(202) 260-7751

Indoor Air Quality Information Clearinghouse (IAQ INFO)
P.O. Box 37133
Washington, DC 200137133
(800) 438-4318
(301) 585-9020

Operates Monday to Friday from 9 to 5 Eastern Standard Time
(EST). Distributes EPA publications, answers questions on the
phone, and makes referrals to other nonprofit and governmental
organizations.

National Radon Hotline
(800) SOS-RADON
Information recording operates 24 hours a day.

National Lead Information Center
(800) LEAD-FYI

Operates 24 hours a day, seven days a week. Callers may order an
information package. To speak to an information specialist, call
(800)4245323. Operates Monday to Friday from 8:30 to 5 EST.

National Pesticides Telecommunications Network
National toll free number: (800) 858-PEST
In Texas: (806) 7433091

Operates Monday to Friday from 8 to 6 Central Standard Time.
Provides information about pesticides to the general public and
the medical, veterinary, and professional communities.

RCRA/Super fund Hotline
National toll free number: (800) 4249346
In Washington, DC area: (703) 4129810

Operates Monday to Friday from 8:30 to 7:30 EST. Provides
information on regulations under both the Resources Conservation
and Recovery Act (including solid and hazardous waste issues) and
the Superfund law.

Safe Drinking Water Hotline
(800) 4264791

Operates Monday to Friday from 8:30 to 5 EST. Provides
information on regulations under the Safe Drinking Water Act,
lead and radon in drinking water, filter information, and a
list of state drinking water offices.

TSCA Assistance Information Service
(202) 5541404

Operates Monday to Friday from 8:30 to 5 EST. Provides
information on regulations under the Toxic Substances Control Act
and on EPA's asbestos program.

U.S. Consumer Product Safety Commission (CPSC)
Washington, DC 202070001
Product Safety Hotline: (800) 638-CPSC

Teletypewriter for the hearing impaired (outside Maryland): (800)
638-8270; Maryland only: (800) 492-8104. Recorded information is
available 24 hours a day when calling from a touch tone phone.
Operators are on duty Monday to Friday from 10:30 to 4 EST to
take complaints about unsafe consumer products.

U.S. Department of Housing and Urban Development
Office of Energy and the Environment
Washington, DC 20410
HUD USER National toll free number: (800) 245-2691
In Washington, DC area: (301) 251-5154.

U.S. Department of Energy
Office of Conservation and Renewable Energy
1000 Independence Ave., SW
Washington, DC 20585

Conservation and Renewable Energy Inquiry and Referral Service
(CAREIRS)
PO Box 3048, Merrifield, VA 22116; (800) 523-2929.

Operates Monday to Friday from 9 to 5 EST. Provides consumer
information on conservation and renewable energy in residences.

U.S. Public Health Service
Division of Federal Occupational Health
Office of Environmental Hygiene, Region III, Room 1310
3535 Market St., Philadelphia, PA 19104
(215) 596-1888; fax: 215-596-5024

Provides indoor air quality consultative services to federal
agency managers.

Centers for Disease Control and Prevention
Lead Poisoning Prevention Branch
4770 Buford Highway, NE (F42), Atlanta, GA 30341-3724
(800) 488-7330

Office on Smoking and Health
Centers for Disease Control and Prevention
U.S. Department of Health and Human Services

4770 Buford Highway, NE (K50), Atlanta, GA 30341-3724
(404) 488-5701

Occupational Safety and Health Administration
Office of Information and Consumer Affairs
Room N-3647
200 Constitution Avenue, NW, Washington, DC 20210
(202) 219-8151

Bonneville Power Administration
Portland, OR 97208

General Services Administration
18th and F Streets, NW, Washington, DC 20405

Tennesee Valley Authority

Industrial Hygiene Branch

Multipurpose Building (1B), Muscle Shoals, AL 35660

State and Local Organizations

Your questions or concerns about indoor air problems can
frequently be answered by the government agencies in your state
or local government. Responsibilities or indoor air quality
issues are usually divided among many different agencies. Calling
or writing the agencies responsible for health or air quality
control is the best way to start getting information from your
state or local government. To obtain state agency contacts, write
or call EPA s IAQ Information Clearinghouse, (800) 4384318.

CPSC REGIONAL OFFICES

Eastern Regional Center
6 World Trade Center
Vesey Street, 3rd Floor Room 350
New York, NY 10048-0950
(212) 466-1612

Central Regional Center
230 South Dearborn Street Room 2944
Chicago, IL 60604-1601
(312) 353-8260

Western Regional Center
600 Harrison Street Room 245
San Francisco, CA 94107
(415) 744-2966

States in Region
Connecticut, District of Columbia, Delaware, Florida,
Massachusetts, Maryland, Maine, North Carolina, New Hampshire,
New York, Pennsylvania, South Carolina, Rhode Island, Virginia,
Vermont, West Virginia

Alabama, Georgia, Iowa, Illinois, Indiana, Kansas, Kentucky,
Michigan, Minnesota, Missouri, Mississippi, North Dakota,
Nebraska, Ohio, South Dakota, Tennessee, Wisconsin

Alaska, Arkansas, Arizona, California, Colorado, Hawaii, Idaho,
Louisiana, Montana, New Mexico, Nevada, Oklahoma, Oregon, Texas,
Utah, Washington, Wyoming

EPA REGIONAL OFFICES

Address inquiries to the Indoor Air Coordinators in the EPA
regional offices at the following addresses:

Region 1
EPA
John F. Kennedy Federal Building
Boston, MA 02203
617-565-4502

Region 2
EPA (2AWM-RAD)
26 Federal Plaza
New York, NY 10278
212-264-4418

Region 3
EPA
841 Chestnut Building
Philadelphia, PA 19107
215-595-8322
215-597-4084 (radon)

Region 4
EPA
345 Courtland Street NE
Atlanta, GA 30365
404-347-2864

Region 5
EPA AT-18L
77 W. Jackson Blvd.
Chicago, IL 60604
312-353-2205

Region 6
EPA
First Interstate Bank Tower
1445 Ross Avenue
Dallas, TX 75202
214-655-7223

Region 7
EPA ARTX / ARBR-RAID
726 Minnesota Avenue
Kansas City, KS 66101
913-551-7222

Region 8
EPA 999 18th Street, Suite 500
Denver, CO 80202-2466
303-293-1709

The following organizations have information discussed in this
booklet. EPA s IAQ Information Clearinghouse, (800)438-4318, can
provide the names of a variety of organizations that have
information on all of the issues discussed in this publication.

American Association of Poison Control Centers
3800 Reservoir Rd., NW
Washington, DC 20007

American Society of Heating, Refrigerating, and Air-Conditioning
(ASHRAE)
1791 Tullie Circle NE
Atlanta, GA 30329

World Health Organization
Publications Center
49 Sheridan Avenue
Albany, NY 12210

Your local American Lung Association (ALA)
1740 Broadway
New York, NY 10019
(800) LUNG-USA

GLOSSARY

Acid aerosol
Acidic liquid or solid particles that are small enough to become
airborne. High concentrations of acid aerosols can be irritating
to the lungs and have been associated with some respiratory
diseases, such as asthma.

Animal dander
Tiny scales of animal skin.

Allergen
A substance capable of causing an allergic reaction because of an
individual s sensitivity to that substance.

Allergic rhinitis
Inflammation of the mucous membranes in the nose that is caused
by an allergic reaction.

Building-related illness
A discrete, identifiable disease or illness that can be traced to
a specific pollutant or source within a building. (Contrast with
Sick building syndrome ).

Chemical sensitization
Evidence suggests that some people may develop health problems
characterized by effects such as dizziness, eye and throat
irritation, chest tightness, and nasal congestion that appear
whenever they are exposed to certain chemicals. People may react
to even trace amounts of chemicals to which they have become
sensitized.

Environmental tobacco smoke
Mixture of smoke from the burning end of a cigarette, pipe, or
cigar and smoke exhaled by the smoker (also secondhand smoke or
passive smoking).

Fungi
Any of a group of parasitic lower plants that lack chlorophyll,
including molds and mildews.

Humidifier fever
A respiratory illness caused by exposure to toxins from
microorganisms found in wet or moist areas in humidifiers and air
conditioners. Also called air conditioner or ventilation fever.

Hypersensitivity pneumonitis
A group of respiratory diseases that cause inflammation of the
lung (specifically granulomatous cells). Most forms of
hypersensitivity pneumon-itis are caused by the inhalation of
organic dusts, including molds.

Organic compounds
Chemicals that contain carbon. Volatile organic compounds
vaporize at room temperature and pressure. They are found in
many indoor sources, including many common household products and
building materials.

Picocurie
A unit for measuring radioactivity, often expressed as picocuries
per liter of air.

Pressed wood products
A group of materials used in building and furniture construction
that are made from wood veneers, particles, or fibers bonded
together with an adhesive under heat and pressure.

Radon and radon decay products
Radon is a radioactive gas formed in the decay of uranium. The
radon decay products (also called radon daughters or progeny) can
be breathed into the lung where they continue to release
radiation as they further decay.

Sick building syndrome
Term that refers to a set of symptoms that affect some number of
building occupants during the time they spend in the building and
diminish or go away during periods when they leave the building.
Cannot be traced to specific pollutants or sources within the
building. (Contrast with Building related illness ).

Ventilation rate
The rate at which indoor air enters and leaves a building.
Expressed in one of two ways: the number of changes of outdoor
air per unit of time (air changes per hour, or ach ) or the rate
at which a volume of outdoor air enters per unit of time (cubic
feet per minute, or cfm )